# When to use a SIP and when to invest a lump sum

Source: https://koshex.com/blog/when-is-the-right-time-to-invest-in-lump-sum-and-sip · Published 18 May 2024 · 10 min read

A SIP suits money that reaches you every month. When a sum is already in your account, you can invest it at once or spread it with an STP. Neither is always better. A lump sum does better if prices rise steadily and a SIP if they fall first; nobody knows in advance which will happen.

## Key takeaways

- A SIP suits money that arrives every month; a sum already in your account can go in at once or in parts through an STP.
- With the same ₹15,000 and made-up NAVs, a lump sum ends with more units if prices rise steadily. A SIP ends with more if prices dip first.
- Nobody can tell in advance which path prices will take, and neither route protects you from a fall in NAV.
- Each STP transfer sells units in the source fund and buys in the target fund. So it can bring a gain or loss, and an exit load.
- Keep emergency money aside before investing a windfall, then match the rest to a goal and its time frame.

## SIP or lump sum: which is better?

Neither is better every time. The right one depends on whether the money is already in your account and on how prices move after you invest.

Start with where the money comes from. If it arrives as a salary, a SIP is the natural way in. A SIP (systematic investment plan) invests a fixed amount at regular intervals, usually monthly, and each instalment buys units at that day's price.

If a sum is already sitting with you, the question changes. You are asking how fast to put the money in: all at once, or in parts. The basics of a SIP are in [what is a SIP](https://koshex.com/blog/systematic-investment-plan-sip), so this article stays on the comparison.

## What is a lump sum investment?

A lump sum investment puts a larger amount into a fund at one time, so all of it buys units at one day's NAV. The NAV is the price of one unit of the fund.

The arithmetic is plain. A tiny stamp duty is deducted from each purchase, so slightly fewer units are bought. Units allotted equal the amount invested, after stamp duty, divided by the applicable NAV. So ₹5,000 at a NAV of ₹50 buys 100 units, before stamp duty.

Each fund sets its own minimums, and they differ. One fund's scheme document asks ₹1,000 for a lump sum and ₹100 for a SIP instalment, with at least 6 instalments. Another fund's document asks ₹10,000 for a lump sum.

There is no entry load, which means no fee for buying. For most funds, the price is the closing NAV of the day your money is available to the fund. The cut-off for it to reach the scheme's account is 3:00 pm. Liquid and overnight funds follow a different timing rule.

To see what a lump sum could become, try the [lump sum calculator](https://koshex.com/calculators/lumpsum-calculator). The yearly return you type in is an assumption, not a promise. The [SIP calculator](https://koshex.com/calculators/sip-calculator) does the same for monthly amounts.

## When does a lump sum come out ahead, and when does a SIP?

A lump sum ends with more units if prices rise after you invest. A SIP ends with more units if prices fall first and then recover.

Here is the same ₹15,000 put in two ways, using made-up NAVs over three months. The lump sum goes in on day one. The SIP puts in ₹5,000 each month.

| Path | NAVs over three months | ₹15,000 lump sum in month 1 | ₹5,000 SIP each month | Value at ₹100 |
| --- | --- | --- | --- | --- |
| Rising | ₹50, ₹75, ₹100 | 300 units | 216.67 units | Lump sum ₹30,000, SIP ₹21,667 |
| Dip, then recover | ₹100, ₹50, ₹100 | 150 units | 200 units | Lump sum ₹15,000, SIP ₹20,000 |

You can check both rows by hand. In the rising path, ₹5,000 buys 100 units at ₹50, then 66.67 at ₹75, then 50 at ₹100. In the dip path, it buys 50, then 100, then 50.

A fixed-amount SIP buys more units when the NAV is low and fewer when it is high. That is called rupee-cost averaging. Its average cost per unit is never above the simple average of the NAVs. That is all averaging does. It does not promise a better result than a lump sum, and the table shows why. It also does not protect you from a fall. Neither route does.

Falls can be deep. The NIFTY 50, an index that tracks 50 companies by fixed rules, went from 6,287.85 on 8 January 2008 to 2,524.20 on 27 October 2008. That is a fall of 59.9%, measured on the price index. Neither route would have spared you that drop in prices. For more on whether a SIP can lose money, read [is a SIP safe](https://koshex.com/blog/is-sip-safe).

### A worked situation: ₹3 lakh from a matured fixed deposit

Say a fixed deposit matures and ₹3 lakh lands in your account. You have a sum in hand, so the choice is speed, not a monthly habit.

Put it in at once, and all of it buys units at one NAV. If prices then rise steadily, you hold more units than a spread-out plan would have given. If they fall, all of it falls with them.

Spread it, say in six equal monthly parts of ₹50,000, and each part buys at that month's NAV. You gain from a dip and miss part of a steady rise. Nobody can tell you in advance which path the market will take.

What you can weigh is your own side. How soon do you need the money, and how large a fall could you sit through without selling?

## Should you wait for a fall or time your SIP?

Waiting for the right moment usually means guessing, and a wrong guess costs you either a rise you missed or a fall you walked into.

Nobody knows the lowest point until it has passed. If you hold cash back for a dip, the market may climb while you wait. If you buy on a dip, it may keep falling.

A SIP takes that guess out of your hands. It keeps buying through falls, and the lower-priced months are the ones that buy more units. That is what makes averaging work. Stopping during a fall removes exactly those purchases. If that thought is tempting, read [should I redeem my funds since the markets are down](https://koshex.com/blog/should-i-redeem-my-funds-since-the-markets-are-down) first. Koshex, as a distributor (a registered intermediary that helps you buy and manage funds), talks you through sharp market falls before you redeem.

What about buying extra when the market falls? That is a lump sum at that day's NAV, and you can add one to a fund you already hold. It carries the same uncertainty as any other lump sum, because a fall can go on after you buy.

Your SIP date is not a timing tool either. [What is a SIP](https://koshex.com/blog/systematic-investment-plan-sip) covers how to pick one.

## Can you use both, or spread a lump sum with an STP?

Yes. You can run a SIP and add lump sums to the same fund. A systematic transfer plan (STP) moves a sum into a fund in regular parts.

### Both in the same fund

A SIP and a lump sum can sit side by side. Each is a separate purchase at its own day's NAV, in the same folio, which is your single account with the fund house. For example, one fund house's scheme document lets you make an additional purchase in a scheme you already hold from ₹100.

### How an STP works

With an STP, your sum sits in one fund, the source scheme. A fixed amount then moves at set intervals into another scheme of the same fund house, the target scheme. The fund house sells units of the source and buys units of the target, each at that day's NAV.

The source is often a liquid fund. A liquid fund invests only in debt that matures within 91 days. Debt means loans to governments, banks or companies. Most listed liquid funds read Low to Moderate on the riskometer, SEBI's risk label, on 29 September 2026.

Terms vary. For example, one fund house's scheme document sets these:

- A minimum of ₹500 per transfer, with at least 6 instalments.
- Daily, weekly, monthly or quarterly transfers.
- The STP stops after 3 failed transfers in a row.
- 5 working days' notice to start or stop.

Another fund house offers fortnightly transfers too, so check your own fund's document.

An STP spreads your purchases. It does not protect the target fund from a fall, and it is not a way to earn assured returns.

### What an STP does to tax and cost

Each transfer is a sale of source units and a purchase of target units. So each one can give a gain or a loss in the source fund. That gain is taxed under the fund's own rules and holding period, which is how long you owned the units. The new units start their own holding period on the transfer date.

A source fund's exit load, a fee some funds charge if you sell within a set time, can apply too. Liquid funds charge a graded exit load only on exits within 7 days, and none from day 7. For liquid fund units bought on or after 1 April 2023, gains are taxed at your slab rate, whatever the holding period. The slab rate is the tax rate for your total income. So a small gain can arise on each monthly transfer.

In the ₹3 lakh example, the money would sit in a liquid fund and move to the target fund in monthly parts. [Liquid funds vs fixed deposits](https://koshex.com/blog/liquid-funds-vs-fixed-deposits) explains the source side, and the [liquid funds page](https://koshex.com/mutual-funds/categories/liquid-funds) lists them.

A systematic withdrawal plan (SWP) is a separate facility, covered in [can I get monthly income from mutual funds](https://koshex.com/blog/can-i-get-monthly-income-from-mutual-funds).

## What should you do with a bonus or other windfall?

Keep enough aside for emergencies first. Then match the rest to a goal and its time frame, and only then pick a lump sum, an STP or a SIP. This holds for a bonus, an FD that matures, or money from selling something.

### Emergency money first

Emergency money comes before any investing. The reason is practical. Selling units takes up to three working days, and equity values, the value of company shares, can sit well below cost for months. A sudden expense could force you to sell when prices are low, or make you stop the SIP. If you want a size, [where should you keep your emergency savings](https://koshex.com/blog/where-should-you-keep-your-emergency-savings) suggests three to six months of expenses.

### Then the goal and the time frame

What is the rest for, and when will you need it? [How much should I invest in mutual funds every month](https://koshex.com/blog/how-much-should-i-invest-in-mutual-funds-every-month) shows how to work from a goal. Koshex helps you choose a fund that suits your goal and timeline. If you would rather raise an existing SIP than invest a lump sum, [step-up SIP](https://koshex.com/blog/step-up-sip) explains how.

### ELSS for tax saving

An ELSS (equity linked savings scheme) is a tax-saving fund. Under the old tax regime only, section 123 (the old Section 80C) allows a deduction of up to ₹1,50,000 a year across all eligible items. The old regime is the older set of tax rules, which you choose instead of the default. ELSS is one of the eligible items under section 123 of the Income-tax Act, 2025.

An ELSS must keep at least 80% in equity and equity-related instruments. Each purchase is locked for three years from its own allotment date, so a lump sum and each SIP instalment have separate lock-ins. Koshex helps with the ELSS and section 123 decision each financial year. See [ELSS funds](https://koshex.com/mutual-funds/categories/elss-funds) for the category.

### Tax is the same either way

Tax depends on the fund and on how long you hold each unit, not on whether you used a SIP or a lump sum. Each SIP instalment has its own holding period. The rates are in [how SIP returns are taxed](https://koshex.com/blog/how-sip-returns-are-taxed). You can also browse [mutual funds](https://koshex.com/mutual-funds) on Koshex.

## Frequently asked questions

### When should I invest a lump sum and when should I use a SIP?

A SIP suits money that reaches you every month. When a sum is already in your account, you can invest it at once or spread it with an STP. Neither is always better, because a lump sum does better if prices rise steadily and a SIP does better if they fall first.

### Is a SIP always more profitable than a lump sum?

No. With made-up NAVs of ₹50, ₹75 and ₹100, a ₹15,000 lump sum buys 300 units and a ₹5,000 monthly SIP buys 216.67. With NAVs of ₹100, ₹50 and ₹100, the lump sum buys 150 units and the SIP buys 200. The result depends on the path prices take.

### Can I invest a lump sum and a SIP in the same fund?

Yes. Each is a separate purchase at its own day's NAV, and both sit in the same folio. One fund house's scheme document, for example, allows an additional purchase in a scheme you hold from ₹100.

### Is now a good time to start a SIP?

Nobody can know that, and guessing can cost you a rise you missed or a fall you walked into. A SIP suits a monthly amount you can keep steady. Averaging works by buying through low-priced months, so it needs time to do that.

### What is an STP?

A systematic transfer plan moves a fixed amount at set intervals from one scheme to another scheme of the same fund house. Each transfer sells units of the source and buys units of the target at that day's NAV. So each one is a sale and a purchase, and it can carry a gain, a loss or an exit load.

### Is the tax different for a SIP and a lump sum?

No. Tax depends on the type of fund and how long you hold each unit, not on the route. Each SIP instalment is a separate purchase with its own holding period.

### What is a lump sum investment?

It is a larger amount put into a fund at one time, so all of it buys units at one day's NAV. Minimums differ by fund: one fund asks ₹1,000 and another ₹10,000. There is no entry load.

*This article explains how things work; it is not advice to buy or sell any investment. Mutual fund investments are subject to market risks, read all scheme related documents carefully.*